Figure 38-5: Mycobacteriophage lysis genes.  With the exception of phage Rosebush, all of the sequenced mycobacteriophage genomes along with the partially sequenced Ms6 genome contain two genes encoding putative lytic enzymes used for degradation of the cell wall at the completion of lytic growth.  The putative lysA genes (light gray boxes) form a family of related sequences but the relationships are complex and not all pairs of genes have detectable sequence similarity.  The lysB genes (dark gray boxes) are also implicated in lysis.  Putative holin genes (diagonally striped boxes) can be identified in six of the phages, with L5 11, D29 11 and Cjw1 33 formed one set of related genes, Che8 34 and Ms6 4 another, and Bxz1 gp237 a third.